Form 42
                             Apportionment and Combined Reporting Adjustments                                                                                  2024
                             Include with Idaho Income Tax Return as Page 3
Name as shown on return                                                                                                 Federal Employer Identification Number (EIN)

Part I.  Apportionment Formula                                                            Check if using three factor apportionment                          ▪
Property (Owned Property at Original Cost)
                                                                                            Total                        Idaho                                 Percentage
Beginning of Year
1.  Inventories ...................................................................... 1  ▪                            ▪
2.   Real and tangible personal property ..............................                2  ▪                            ▪
Ending of Year
3.  Inventories ...................................................................... 3  ▪                            ▪
4.   Real and tangible personal property ..............................                4  ▪                            ▪
5.   Total of lines 1 through 4 ................................................       5 
6.   Average. Line 5 divided by 2 ..........................................           6 
7.   Rented property (capitalized at 8 times rents paid) ........                      7  ▪                            ▪
8.  Total property. Add lines 6 and 7 ....................................             8  ▪                            ▪
9.   Idaho property percentage. Compute percentage to four decimal places ...........................................                                     9              %
Sales (Gross Receipts)
10.  Gross sales, less returns and allowances ......................                   10 ▪
11.  Sales delivered or shipped to Idaho purchasers ............                       11                              ▪
12.  Idaho “throwback” sales .................................................         12                              ▪
13.  Sales of services ............................................................    13 ▪                            ▪
14.  Other business gross receipts ........................................            14 ▪                            ▪
15.  Total gross receipts. Add lines 10 through 14 .................                   15 ▪                            ▪
16.  Idaho sales percentage. Compute percentage to four decimal places ..............................................                                     16             %
17.  Reserved ........................................................................................................................................... 17 
Payroll
18. Total wages and salaries .................................................         18 ▪                            ▪
19.  Idaho payroll percentage. Compute percentage to four decimal places ............................................                                     19             %
20.  Total Percentage. See instructions ...................................................................................................               20             %
21.  Idaho Apportionment Factor. See instructions ...............................................................................                         21             %
Part II.  Combined Reporting Adjustments                                                                                 Water’s Edge                          Worldwide
Additions
1.   Income of unitary foreign subsidiaries. See instructions ..................................                    1                                         ▪
2.   Federal taxable income of unitary subsidiaries not included on the federal return ....                         2  ▪                                      ▪
3.   Income of foreign corporations subject to federal taxation ...............................                     3  ▪
4.   Intercompany transactions eliminated on the federal return ............................                        4  ▪                                      ▪
5.   Other additions. Include explanation ................................................................          5  ▪                                      ▪
6.   Total additions. Add lines 1 through 5. Enter on Form 41, line 17 ....................                         6 
Subtractions
7.   Federal taxable income of nonunitary subsidiaries included on the federal return                               7  ▪                                      ▪
8. Exclusion for foreign dividends
     a. Foreign dividends ......................................................................................... 8a ▪
     b. Enter 80% if no spreadsheets filed or 85% if spreadsheets filed ................. 8b                                                              %
     c. Dividend exclusion. Multiply line 8a by line 8b .............................................               8c ▪
9.   Intercompany dividends included on the combined return ...............................                         9  ▪                                      ▪
10.  Intercompany transactions included on the federal return ...............................                       10 ▪                                      ▪
11.  Other subtractions. Include explanation ...........................................................            11 ▪                                      ▪
12.  Total subtractions. Add lines 7, 8c, 9, 10, and 11. Enter on Form 41, line 29 .....                            12 
EFO00029     07-09-2024 

                     Form 42 — Instructions
                     Apportionment and Combined Reporting Adjustments

Part I of this form provides the computation of       Property 
the Idaho apportionment factor and is used by                              Enter the beginning and end 
                                                      Lines 1 through 4.
taxpayers who have income from business activity      of the year total property and Idaho property 
that’s taxable in Idaho and another state or country. amounts.
If the taxpayer is a partner in a partnership or a 
shareholder in an S corporation, the taxpayer must    Line 9. Divide Idaho property by total property 
take into account the activity of the pass-through    (amounts on line 8).

entity in determining whether the taxpayer has              
                                                      Sales
income from business activity that’s taxable in Idaho 
and another state or country. Include the taxpayer’s  Lines 11 and 12. Enter the amounts from line 10 
share of the pass-through entity’s property, payroll, that were delivered or shipped to Idaho buyers 
and sales numbers from Form ID K-1 in the             (line 11) or that were throwback sales to Idaho 
amounts reported on this form.                        (line 12). A sale made in a state with no jurisdiction 
                                                      to tax the seller is a throwback sale.
Part II of this form provides the worldwide and 
water’s-edge adjustments to compute combined          Line 14. Include a detailed schedule.
income. Part II is used by a corporation that has 
                                                      Line 16. Divide Idaho gross receipts by total gross 
ownership in at least one foreign affiliate.
                                                      receipts (amounts on line 15.)
Partnerships don’t use Part II.
                                                      Payroll
Factor information is available at tax.idaho.gov.
                                                      Line 19. Divide Idaho wages and salaries by total 
Part I Specific Instructions                          wages and salaries (amounts on line 18).

Instructions are for lines not fully explained on the Total Percentage
form. Compute all percentages to four places to       Line 20. For taxpayers using the three-factor 
the right of the decimal point (00.0000%). Include    apportionment method, add the percentages on 
a schedule showing apportionment detail by            lines 9, 16 and 19. 
company if filing for a unitary group.
Single sales factor is the default apportionment      For all other taxpayers, use the percentage on line 
method. Electrical, telephone and                     16.

communications corporations (as defined in            Idaho Apportionment Factor
Idaho Code) and Multistate Tax Commission 
(MTC) special industries (construction                Line 21.  For taxpayers using the three-factor 
contractors, airlines, railroads, trucking            apportionment method, divide the total on line 20 
companies, television and radio broadcasting,         by three.  If any of the factors don’t apply to your 
publishing, and financial institutions) can elect     business, divide the total on line 20 by the number 
to use a three-factor method. If you’re using         of factors used.  For example, if your business has 
three-factor apportionment, check this box            no employee anywhere, your factor is reduced by 
and provide a list of the companies using the         one.
three-factor method.                                  For all other taxpayers, use the percentage on 
All taxpayers must complete all three sections        line 20.
(property, payroll and sales) of Part I. Only 
three-factor taxpayers will use all three factors to 
compute their apportionment factor.

EIN00099 07-09-2024                                                                           Page 1 of 3

                                                    Form 42 —(continued)                                 Instructions 

Part II Specific Instructions                       and that weren’t included in the federal 
To the extent that amounts listed for water’s-edge  consolidated return. This is the amount reported 
filers are different than the amounts listed for    on the subsidiary’s federal income tax return, 
worldwide filers, separate instructions are listed. Form 1120, adjusted for the Idaho additions 
                                                    and subtractions listed on Form 41. Include a 
Additions                                           schedule identifying this income by corporation.

Line 1 Income From Unitary Foreign                  Line 3 Income of Foreign Corporations Subject 
Subsidiaries                                        to Federal Taxation
Water’s-edge Filers. Disregard this line and go     Water’s-edge Filers. Enter the federal taxable 
to line 2.                                          income reported by corporations incorporated 
If foreign affiliates aren’t included in a          outside the United States that are required to file 
consolidated federal return, the corporation can    a federal income tax return. This includes foreign 
select one of the following options. The option     corporations filing a federal Form 1120F.
selected must be used for all foreign affiliates 
                                                    Worldwide Filers. The income of foreign corporations 
not included in a consolidated federal return and 
                                                    is included on line 1.
must be adjusted for the Idaho additions and 
subtractions listed on Form 41.                     Include a schedule identifying this income by 
                                                    corporation and also include copies of the federal 
Option 1. Enter the net income before income        income tax returns filed by each.
taxes stated on each affiliate’s profit and loss 
statement prepared for the United States            Line 4 Intercompany Eliminations
Securities and Exchange Commission (SEC). If        Enter the amount of intercompany transactions 
the profit and loss statement isn’t filed with the  between the combined group and nonunitary 
SEC, enter the net income or loss before income     subsidiaries eliminated on the federal consolidated 
taxes reported on the profit and loss statement     return. The income of the nonunitary subsidiaries 
prepared for reporting to shareholders that’s       is a subtraction on line 7. Include a schedule 
subject to review by an independent auditor.        identifying the intercompany transactions 
                                                    by corporation.
Option 2. The net income or loss reported on the 
profit and loss statements may be adjusted to       Line 5 Other Additions
tax accounting standards as would be required       Enter any miscellaneous Idaho additions. Include 
by the Internal Revenue Code (IRC) if the           a schedule identifying each miscellaneous addition 
corporation was incorporated in the United States.  by corporation.
If a corporation chooses to make the book-to-tax 
adjustments, all book-to-tax adjustments must       Subtractions
be made for all unitary foreign corporations not 
                                                    Line 7 Federal Taxable Income of Nonunitary 
included in the consolidated federal return. The 
                                                    Subsidiaries Included on the Federal Return
book-to-tax adjustments must be consistently 
applied each year the group files a worldwide       Enter the federal taxable income of nonunitary 
return.                                             subsidiaries included in the federal consolidated 
                                                    return. Include a schedule identifying the income or 
Include a schedule of the foreign affiliate income  loss by corporation.
by corporation. Also include schedules of the 
book-to-tax adjustments, if any.

Line 2 Federal Taxable Income of 
Nonconsolidated Unitary Subsidiaries
Enter the federal taxable income of unitary 
subsidiaries incorporated in the United States 
that are more than 50% commonly owned 

EIN00099   07-09-2024                                                                         Page 2 of 3

                                                                         Form 42 —(continued)                  Instructions 

Line 8 Dividend Exclusion                               Include a schedule identifying payors, payees 
The following dividend exclusions are applicable        and dividend amounts regardless of the filing 
only to water’s-edge filers.                            method.
a. Foreign Dividends. Enter the total amount of 
                                                        Line 10 Intercompany Transactions Included on 
dividends paid by foreign affiliates. Include 
                                                        the Federal Return
the amounts of income from controlled foreign 
                                                        Enter the intercompany transactions between 
corporations under subpart F if included in 
                                                        members of the combined group that haven’t 
federal taxable income. Enter the income from 
                                                        otherwise been eliminated.
possession corporations included in line 2. 
Don’t include on this line any actual dividends         Line 11 Other Subtractions
paid by the possession corporations.                    Enter any miscellaneous Idaho deductions. 
b. Exclusion Percentage. If you elected to forgo        Include a schedule identifying each miscellaneous 
filing the water’s-edge spreadsheets as shown           deduction by corporation.
on line 8b, Form 41, enter 80%. Enter 85% 
if you’re filing the water’s-edge domestic 
disclosure spreadsheets.

Line 9 Intercompany Dividends Included on 
the Combined Return
Enter the amount of dividends paid by one 
member to another member of the unitary group 
that haven’t been subtracted elsewhere on this 
form or Form 41.

                                             Contact us:
                    In the Boise area: (208) 334-7660   Toll|free: (800) 972-7660
                             Hearing impaired (TDD) (800) 377-3529
                                       tax.idaho.gov/contact
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